Not only did Smurfette herself, Katy Perry, and her pal, songwriter Bonnie McKee, contribute some secret vocals to Britney Spears‘ “Smurfs 2” soundtrack tune, “Ooh La La,” but it was McKee who insured that what they were singing was family friendly.

McKee told MTV News she tweaked the lyrics to take the song from PG-13 steamy to Rated G.

“I actually came in and was the doctor behind it. A lot of it was already written. It was a great song to begin with. … They wanted it for the ‘Smurfs’ movie, and it was originally pretty sexy,” McKee recalled about “Ooh La La,” which features credits from the likes of Dr. Luke, Ammo and Cirkut as well as J Kash, Lola Blanc and Fransisca Hall. “I was like, ‘OK, how do I take this sex-drenched song and make it Smurfs friendly?’

“That was kind of my task, but it still had to work at radio and be something that people would buy as a Britney Spears song because she’s not a Smurf,” she added. “So, it was just kind of fun to find double entendres to put in there and kind of trick the parents into thinking it’s kid friendly.”

Spears has noted that her sons, Smurfs fanatics Jayden and Sean, served as an inspiration for her to record the track for the movie. “I think Britney is in a different place, and she’s a mother, and it seemed appropriate to kind of Smurf-ify the song,” McKee said. “She’s still a beautiful, sexy, fierce woman in charge, so we had to keep some of the teeth in the song but still make it parent friendly and kid friendly.”

The “Ooh La La” video, featuring Spears’ kids, was released earlier this month. McKee said that when her tunes are brought to life in video form, what she envisions isn’t always what the artist decides on.

“That happens a lot, actually. When I’m writing a song, I usually see a video in my head,” she explained. “So sometimes it’s weird to write the song and have this, ‘It’s so obvious they’re going to take it in this direction.’ And then I actually see the video, and I’m like, ‘Oh, OK, that’s not what I would have done, but OK.'”

However, in the case of the “Ooh La La” video, she was totally down for the concept of Spears cavorting with the blue creatures. “Love it! What else would I ever want to see but Britney Spears dancing with Smurfs?” she said. “That’s what I live for!”

“Smurfs 2” opens Wednesday. Perry not only added her own ooh la la to Spears’ song, but also reprises her role as the female Smurf in the sequel to the 2011 flick, alongside Neil Patrick Harris, “Glee” star Jayma Mays and Hank Azaria.